My wife and I recently went on a 7day Eastern Caribbean cruise (early Feb) for 188 points per adult, Category 7 (Navigator's Verandah). During the time last year that I booked the trip, I also looked at the price if I were to pay by cash. Assuming that I could get $10 per point on rental, I think the cost with points was about the same as with cash. Since I had never put my points for rent, I didn't want to bother with the whole process. So, I used my points for the cruise, and I have no regrets. The way I look at it, you are spending more points to go on a cruise than if you were to stay at a
DVC resort for a week (perhaps), but all the costs of food and entertainment on the cruise are included. If I were to go to WDW, I would have to buy groceries or go out for meals, then also pay for tickets to various parks or shows. On a cruise, everything is included, except for your alcohol, shore excursions, and merchandise. If you have kids, they even have activities for them, so you can even get away from your kids.
While I was onboard the ship, I met other DVC members who used their points for the cruise. While on the ship, you can also book the next cruise with fewer points.
I agree with another post: I would not buy the points just to go on a cruise. I think of the cruise as an option for more variety in your vacation. Also, I think paying cash for the kids is maybe better than using points.
For us, with a baby coming, we needed to use up our points for this use year, as well as some of next use year, when we will be too preoccupied with the baby. I will plan on banking the rest of my points for my next use year, so I don't have to worry about how I can use my points.